The prior art discloses a number of ways to achieve desired illumination of a target.
For example, U.S. Pat. No. 6,672,739 concerns a laser beam homogenizer. This apparatus was developed for the illumination of lithographic masks, or more specifically, an object in a microscope. The output of a laser beam homogenizer is imaged onto a field for wide field illumination. The image of the output is dithered with respect to the field. However, this apparatus requires that the illuminating ray bundle must be injected into the lens along a plane defined by one of the great arcs on the lens surface and the light polarization must be parallel- or perpendicular to that plane. Further limitations of this apparatus include image distortion due to residual non-uniform background illumination.
U.S. Pat. No. 4,011,403 involves fiber optic laser illuminators. This apparatus is an endoscopic or microscopic illumination and imaging system for a surgical area. It uses a laser beam as a light source, an optical fiber as a transmitter, and a sensing means to display an illuminated object. Speckle reduction is available with the use of a light-flow-disruptive means acting on a collimated line of illumination.
U.S. Pat. No. 8,372,004 pertains to speckle reduction of microwhite endoscopes. It consists of an actuator, a light source, a light-conducting element, and a fluorescence converter. This assembly generates perturbations or fluctuations to reduce speckles in an endoscopic image. However, transmission of motor vibrations onto the housing or other components of the proximal supply unit can cause unintended disturbances of the endoscopic system.
Notwithstanding the above known the prior art illumination arrangements and techniques, there still remains a need for improved uniform illumination of a desired target, by use of at least one laser, which facilitate improved imaging of the illuminated target by an imaging system.